Knowledge Hub

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The Knowledge Hub is evolving, and we plan to deliver more resources, tools, webinars and structured learning, which will support road managers and industry to better understand the relationship between asset capability across a range of vehicle configurations.

We want to know how we can support you, please take the survey below to provide feedback on what learning resources you would like:

On this page:

Asset Nomination

A further Round is scheduled for Phase 2. To nominate your assets for future rounds, please express your interest in SLGAAP by nominating your asset via the NHVR Portal. For detailed steps on how to nominate - download the Nomination Guide. For more information, see Asset Nomination

Asset Assessment Framework and Processes - Flowchart (Updated May 2022)

This process document gives you a decision framework, helping you decide the best type of engineering assessment needed to support an access decision on your network.

Use the Asset Assessment Framework to help you:

  • Understand how to define your bridge capability
  • Learn the Bridge assessment and access terminology used throughout Australia
  • Understand the various tiers of assessment and when to employ them 

This process document gives you a decision framework, helping you can decide the best type of engineering assessment needed to support an access decision on your network.


How can state and territory jurisdictions support the project?

  • Share project information with transport operators
  • Promote the benefits of the project to industry
  • Provide road asset data if available and on request
  • Assist with the identification of key heavy vehicle routes


What is a 'valid' inspection report?

A valid inspection is considered any current Level 2 inspection that has been undertaken and reported using the processes and formats of the relevant State bridge inspection manual. These types of inspections are detailed inspections where every element is inspected and systematically given a condition rating (1-4) and all major defects are systematically logged and described using the relevant template/format as specified in the relevant State bridge inspection manual. 

A Level 2 inspection is preferred, however, please upload a Level 1 if that is all that is available.  

In terms of currency, an inspection needs to have been undertaken within the current inspection cycle for a structure. The recommended intervals between inspections are documented in the relevant state bridge inspection manual and can vary from jurisdiction to jurisdiction and are often based on the material type and the condition found during the previous inspection. 

As a guide: 

  • Concrete: No more than 5 years since the last inspection. 

  • Steel: No more than 3 years since the last inspection. 

  • Timber: No more than 2-3 years since the last inspection. 

Level 1     

Routine Maintenance Inspection (Level 1) - a visual inspection to check the overall serviceability of the structure and identify maintenance issues. 

Level 2 

Detailed Component Condition Inspection (Level 2) - consists of a detailed report outlining the condition state of every structural component and a log of significant defects. 

Level 3 

Detailed Structural Engineering and Material Inspection (Level 3) – usually focuses on defect identification and quanitification and site specific investigation of certain parameters to reduce uncertainty and improve assessments of capability. 


Where can I find state asset inspection manuals?

You can find inspection manuals for your relevant state or territory: 


What is required of council if asset submission is successful?

The asset assessment is undertaken by engineering consultants, who are funded through SLGAAP. Although no monetary contributions will be required from participating councils, there is a time cost to participate in an onboarding session, ad hoc progress meetings, and a completion meeting with NHVR SLGAAP Team and the engineering suppliers. A post-assessment meeting will also be required.


What is the difference between an inspection and an assessment? 

The key difference between a Level of Inspection Report and Tiers of Assessment is purpose:

  • Inspection reports detail asset condition and maintenance.
  • Tiers of Assessment detail the asset capacity for vehicles and loads\

See Key terms for more detail. 


What Tier of assessment report will I receive for my assets?

The SLGAAP team funds external engineering consultants to work with participating road managers. The SLGAAP team, in collaboration with the engineering consultant, will decide what tier of assessment can be completed based on the asset information available to them and submitted at time of nomination.


What should I do if the asset's Design Standard is unknown?

Please enter the closest assumed design standard from the drop-down list, or ‘UDL’ and enter in the comments field ‘unknown design standard, please refer to construction year’. 


Why are inspection reports required?

The engineering assessments are performed using a number of assumptions. For an asset without a recent inspection report, more assumptions are used and may negatively impact the assessment or provide an inaccurate result. Inspection reports provide more accuracy.


Why are Route IDs required?

In Phase 1, we encountered many instances where the coordinates were incorrect and went unrealised until the suppliers were performing the assessment and/or were on site. This is a way to help us mitigate these issues. We will be overlaying the Route ID’s with identified priority routes.

Key terms

Types of SLGAAP assessments

Types Asset Assessment Detail
Tier 1

Tier 1 bridge assessments are performed using the reference vehicle technique, comparing the worst load effects of an application vehicle on a given structure compared to a reference vehicle which would be considered suitable to travel over the structure. Key inputs to the assessment are:

  • Span Length
  • Span Continuity
  • Design Vehicle or known Acceptable Loading Configuration
  • Level 2 Structure Condition (includes design drawings fully defining all geometry and reinforcing, any material specifications used that define required material performance and as-built records – whether as-built drawings if available).
Tier 1/2D Using either an in-lane design vehicle or a known historic in lane vehicle, determine the equivalent rating for straddling lane vehicles using a grillage analysis based on measured section properties. Used in situations where the internal design details are not known and an accurate straddling lane reference vehicle is needed to be produced from existing in lane design/known vehicles.
Tier 2

A Tier 2 bridge assessment focuses on using structural engineering principles to identify the theoretical maximum load effects the structure can withstand as governed by the material and configuration (capacity assessment). Two-dimensional analysis techniques such as a grillage analysis or a line model analysis using girder distribution factors are typically used to determine the theoretical loads from the application vehicle load case. The results of the loading analysis are then compared to a theoretical estimate of the structural capacity of each member of the bridge.

Key inputs to the assessment are:

  • As-Built Drawings (if available),
  • Component Geometries and Material Properties to construct analytical models,
  • Site Measurements (if necessary),
  • Assessment Vehicles, and Level 2 Structure Condition.
Tier 3 Assessment or testing activities that employ methodologies other than typically accommodated in the Australian Standards, including potential benefits over and above a Tier 2 asset assessment.
Asset Improvement Report (AIR)

Where assets do not have the capacity to support the desired heavy vehicle movements on the network an Asset Improvement Report will outline the actions required to improve the asset capacity; repair or renewal.


Types of Asset/ Bridge Inspection Reports

Level 1 Routine Maintenance Inspection (Level 1) - a visual inspection to check the overall serviceability of the structure and identify maintenance issues.
Level 2 Detailed component Condition Inspection (Level 2) - consists of a detailed report outlining the condition state of every structural component.
Level 3 Detailed Structural Engineering and Material Inspection (Level 3) - analytical analysis of a structure with suitable defect identification and investigation.


SLGAAP Webinar Series

To support road managers in undertaking heavy vehicle assessments of their bridge and culvert assets, the NHVR ran a series of webinars from July-August 2021.

Sessions recordings and resources are listed below (view YouTube playlist):






Webinar 1 - The Strategic Local Government Asset Assessment Project

  • Responsibilities under the HVNL
  • Customer Perspective
  • Assessments and how they relate to HV access decisions
  • Introduction to bridge assessments v inspections


Video Link:

Presentation Slides



Webinar 2 - Basic Vehicle/ Bridge Interactions

  • Simple v continuous
  • Tiers of assessment
  • Ground Contact width

Video Link:

Presentation Slides



Webinar 3 - Asset Assessment Framework

  • Review and application of framework

Video Link:

Presentation Slides
Asset Assessment Framework



Webinar 4 - Tier 1 Assessments

  • Data requirements
  • Valid Tier 1

Video Link:

Presentation Slides



Webinar 5 - Engineering Reports on Assets

  • How the results of an engineering report can support heavy vehicle access decision making

Video Link:

Presentation Slides



Webinar 6 - Vehicles and Route Assessment

  • Using available engineering reports
  • Past decisions/ similar structures

Video Link:

Presentation Slides



Webinar 7 - Applying Conditions for Heavy Vehicle Access

  • Common conditions
  • Adding conditions
  • Using an alternative route

Video Link:

Presentation Slides




Webinar 8 - NHVR Portal Digital Asset Management

  • NHVR Portal Map Layer
  • NHVR Portal Digital Asset Management Module
  • How to publish your asset data

Video Link:

Presentation Slides



Webinar 9 - Pre-approvals for key routes

  • Considerations for adding route
  • Determining usage/ permit volumes
  • Completing the pre-approvals form

Video Link:

Presentation Slides


Technical Information Webinars for road managers that may be of interest when assessing assets for Class 1 and PBS vehicles:

Session 1 - NHVR and Local Road Manager Webinar

Session 2 - Application of Bridge Formulae and HVNL Exceptions

Session 3 – Performance-Based Standards (PBS)

Session 4 – Class 1 OSOM/SPV

Session 5 – Class 1 Agricultural

Session 6 – Vehicle and Route Assessment

Session 7 – Structural Assessment

Session 8 – Road Manager Experiences


NHVR Website - Local government road managers

As a road manager, you are responsible for consenting to access for restricted access vehicles on your roads and the conditions under which they will operate. It is important that you understand your role under the HVNL, as well as how to approve access to your road network through the NHVR Portal. 

Some of the topics included on the NHVR Website for local government road managers:

  • Getting started: Understanding the roles and responsibilites of a road manager under the HVNL. 
  • Approved Guidelines for Granting Access: The Approved Guidelines for Granting Access contains high-level guidance and clarity on aspects of heavy vehicle access decision-making under the HVNL. The HVNL requires that road managers, road authorities and the NHVR must 'have regard to' these guidelines. 
  • Performance Based Standards (PBS): The benefits of the PBS Scheme and how to assess PBS requests. 

Trucks and configurations

A guide on basic truck information and terminology.


Vehicle Comparison tool for Bridges (VCB) formerly Asset Rapid Assessment Tool (ARAT) (Calculation tool)

The Vehicle Comparison tool for Bridges (VCB) (formerly ARAT) provides an equivalent outcome to a Tier 1 Asset Assessment, comparing a reference vehicle to the specific vehicle configuration requesting access. It is planned that the tool will be available to both industry (applying for heavy vehicle access) and road managers (assessing heavy vehicle access) via the NHVR Portal. User Acceptance Testing (UAT) of the prototype was completed in 2021, with its staged integration into the NHVR Portal.

For more information, see SLGAAP Vehicle Comparison tool for Bridges (VCB)

Australian Literature

The Higher Order Bridge Assessment in Australia (Austroads 2018) - This report documents the options and methodologies available to conduct higher order assessments of existing bridges which are encouraged by but not currently defined by the new AS 5100.7.
Investigation and Development of Bridge Formulae for Inclusion in the Performance Based Standards (Austroads 2020) - The National Transport Commission review of the Australian Performance-Based Standards (PBS) scheme revealed the need to improve the efficiency of heavy vehicle access via the PBS scheme to access substantial national freight productivity, safety and environmental outcomes.The project reference group resolved to recommend that a line model comparison methodology be implemented to drive a nationally consistent vehicle assessment framework.